Along PCH in north Orange County on any sunny Saturday or Sunday. Hang out at your favorite point along PCH in this area after 8AM for 1 hour and I'll bet you see at least 2 groups. Not sure where they go after getting through the fairly wide streets of Seal Beach/Huntington Beach as the road gets pretty tight along PCH as you continue south into Newport Beach/Laguna Beach/Dana Point

SART on the weekend. Though not as many as along PCH, you'll see them here, too. Odd that most of them seem to be groups of Asian riders. Also smaller 'TT' groups (4-6 persons) going way too fast through the casual recreational riders .